Burglar alarm switching system



March 20, J. T DOQLEY BURGLAR ALARM SWITCHING SYSTEM Filed Aug. 10, 1946\NVENTOR ATTORNEY Patented Mar. 20, 1951 UNITED STATES PATENT OFFICEBURGLAR ALARM SWITCHING SYSTEM John T. Dooley, Buffalo, N. Y.

Application August 10, 1946, Serial No. 689,647

4 Claims.

This invention relates generally to certain new and useful improvementsin burglar alarms, but more particularly to an electrically-governedalarm for safeguarding the public against burglary, hold-ups, fire,kidnapping, and the like.

It has for one of its objects to provide a device of this characterwhich is self-contained, which is sensitive and positive and reliable inoperation, and which is simple, inexpensive and sturdy as well asfool-proof, in construction.

Another object of the invention is to provide an alarm orbody-protecting device which is so designed and constructed as to berendered operative to sound an alarm whenever one attempts unauthorizedintrusion on or into the premises in which the device has been installedto protect.

Other features of the invention reside in the construction andarrangement of parts hereinafter described and particularly pointed outin the appended claims.

In the accompanying drawings Figure 1 is a front elevation of theburglar alarm device installed near the Window of .a room and beingrendered operative by an intruder. Figure 2 is an enlarged sectionalelevation thereof with the trapping cord in its retracted, inop erativeposition. Figure 3 is a cross section of the alarm device taken in theplane of line 3-3, Figure 4. Figure 4 is a longitudinal section of thealarm device taken on line l4, Figure 3. Figure 5 is a diagrammaticperspective view of the electric circuit and parts included therein.

Similar characters of reference indicate the corresponding partsthroughout the several views.

The working parts of my alarm are housed in a casing or cabinet Inproviding a self-contained unit which can be placed where desired forprotective use. In Figure 1, it is shown mounted on a chair with theactuating element or trapping cord H thereof extending adjacent a window22 through which a burglar has partially entered and whose leg hascontacted such cord and rendered the device operative to sound thealarm. The latter may be in the form of a bell 13 contained in thecasing and deriving its power from a battery 14, also housed therein, asshown. If desired, however, other outside alarms may be included in thecircuit or the device may be connected to the lighting circuit of oneshome or building to cause all the lights in the house to go on when thealarm is rendered operative. The trapping cord II has an attaching eye15 or like at its free end for, securing it in its extended position tosome fixed point, such as l6.

Journaled in the casing I0 is a winding drum I! about which the trappingcord H is wound,

its free end extending through the casing and having a pendant weight l8thereon, as shown in Figure 2, for preventing back lash thereof duringrewinding. The drum-shaft H) has a pinion. 2!) thereon meshing with adriven gear 2! in driving engagement with a spring 22 fixed at its innerend to the gear-hub and at its outer end to a pin 23 fixed to a frameplate 24. This spring-driven mechanism constantly urges the cord to itsretracted position, and, as will herein after appear, any motiontransmitted to the drum from a disturbance of the extended cord isutilized to insure closing certain contacts to render the alarmoperative.

The numeral 25 indicates a manually-actuated slide or circuit controlbar guided for horizontal movement within the casing in and at rightangles to but in the axial plane of the drum-shaft l9. At its outer endthis bar is provided with a finger knob 26 and in the full line positionthereof, shown in Figure 4, the alarm circuit is rendered inoperativewhile in the dotted line position of the bar the circuit is pre-set andin readiness to close when the trapping cord is in any way tamperedwith. At its inner end this control bar has a contact 21 thereonterminating in an offset contact lug 28 in operative relation to anotched or bifurcated reset contact arm '29 loosely mounted on thedrum-shaft. This arm is yieldingly urged by a flat spring 30 or the likeinto lateral frictional engagement with the op.- posing cam face 3| of acollar 32 fixed on the drum-shaft I 9, so that during turning of thelatter the reset arm is free to oscillate laterally and have as well aslight vertical rocking movement relative to the lug 28 to make. an onand ofi sliding contact therewith. In the projected or inoperativesetting position of the slide bar, its offset lug extends into andlatches the contact arm in a central or neutral position, so that whensuch bar is retracted to an operative setting position such lug is freefrom contact with the arm until such time as the cord H is disturbed,when the alarm is rendered operative. l

Disposed alongside the bar contact 2-! for circuit-closing engagementtherewith in the re:- tracted, operative setting position of the controlbar 25 is a yielding contact connected by a wire 34 to the coil of amagnet 35, the other side of the coil being connected by a Wire 36, toone of the contacts 31 of a distributing switch. The other contact 38 ofthis switch is connected by a wire 38 to the bell IS, the other terminalof the latter as well as the reset contact arm 29 being connected to thegrounded side of the battery M. The other side of the battery isconnected,v tofa fulcruming-like yieldabl switch blade lflfixed at of alug 42 on the control bar 25, so that in the inoperative settingpositions of the latter such armature assumes the displacedposition-shown in Figure 5 and by full lines in Figure 4, wherein theswitch blade 40 is closed across the contact 31 leading to the magnetcoil.'5.-.In'= the retracted:

operative setting position of the control bar vits armature-engaginglugrecedes therefrom and the contacts 2'! and 33 are closed, with thearmature remaining in its initial "position duejto its frictionaledgewise engagement with the .'.offset portion 43 of the yieldableswitch blade All. .It is this circuit-prepared:condition which thedevice assumes when it is set foruse and to promptly sound the alarmwhen the cord H is disturbed.

Should the cord bedisturbed', for example, as shown irr Figure 1', thedrum I! is partially turned and inso doing' causes the reset contact"arm- 29mg make-contact with the contact-lug ill andmomentarily closethe circuit through the magnet 35. The energizing of themagnet attractsits armatureand-in so doing the latter is released from the switchbladedfi and the latter is-automatically-urged in switch-closingrelation to th contact 38 to render the alarm i2 zopcra- *tive; When thecontrolba-r is pushed inwardly the alarm circuit isopened and the partsassume the positionshown in Figure 5.

If'd'esired, a jack plugfittingM may-be applied torthe-casingl 0, andincluded in the control circuit ofthe devicc'for shuntingthe current toan outside source to sound another alarm or to cause the hous lightingcircuit to be simultaneously closediwhen-the alarm circuit is renderedoperative and result in completeillumination of the .house.

.i I claim as my invention:

. .1. .An alarm-actuating switch mechanism, comprisinganmelectricwcircuit.including a .magnet having an. armature, a switch insaid circuit in- .cluding a-yieldableblade. movable to one or thevotheriof twopositions to establish the circuit of the magnetin one ofsuch. positions, said arma- .ture being disposed in frictional contactwith .said; blade for normally releasably retaining said switch ,in oneiof its .two positions, an auxiliary switch insaid' circuit including onand off presetting contacts. and a third contact movable intocircuit-closing relation with one of said on and Loff contacts, a manualcontrol member on which control member having means thereon engageablewith the armature for. shifting the latter. to its retracted normalposition after it has been actuated to .an operative switch-releasingposition, a cord-winding drumincluding means for normally urging it toturn in a wind-iup direction, and an operative connection between saiddrum and-the third movable contact of'said'auxiliary switch foractuatingsuch contact to an alarmcircuit establishing positionWheneverthe drum is caused toibejturned.

2. An alarm-actuating switch mechanism, comprising an electric circuitincluding a normallyopen switch including a yieldable blade, anauxiliary circuit including a second switch and magnet having anarmature in endwise frictional engagement at one end with said yieldableblade for normally holding the...first-named switch open 'and-thearnrlaturev releasably retracted and causing the closing of such switchand the release of the armature when said magnet is energized, apre-setting, manually-shiftable control member in governing relation tosaid second switch for causing its. closing in one position thereof andits opening in its other position an on and ,i'ofif' displaceablecontactarm in operative relationtoone of the elements of said second switchand" included in the auxiliary circuit thereof for governing thenergization of said magnet, and a rotatable connection to said contactarm-ior causing'its displacement to a position toclose the auxiliarycircuit and energize said magnet.

. 3.. Analarm-actuating switch mechanism, comprising an.electricncircuit.including a normally- .open switch; an auxiliarycircuitincluding a second switch and-magnet having an. armature ingoverning relation to firstenamed' switch. for normally holding it openand causingitsclosing when said magnet issenergized; the. free rendofsaid armatureibeing in camming relation to such first switch-toxretainitopen and the :armature retracted, a presetting, .manually-shiftable.control: member in governing relation to said second switch forcausingrits...closing in'one. position thereof andits opening inxitsother positiongand an on and off, displaceable contact arm' inoperative:relation toaone of the elements of said second switch andincluded in theauxiliary .cir- :cuit athereoffor governing the energization of saidmagnet.

4. An alarm-actuatingswitch mechanism, comprising an electric" circuitincluding a normallyopen switch,-an auxiliary circuitincluding asecond-switchand magnetthatving an armature in governing relationtofirst-named switch for normally holding"- it open and causing itsclosing when-saidmagnet is energized, the free'end of said armaturebeing in cammingrel'ation to such first-switch to retain it open andthearmature rctracted, a presetting, manually-shiftable control member ingoverning relation to said second switch for causing its-closing inoneposition thereof and its-opening in its other position, said controlmember having a part thereon releasably engageable withsaid armature forshifting it to a retracted position when such member is shifted toaswitch-open-ing position, and an "on and off contact arm inoperativerelation to one of the switchelements of said second switch and includedin the auxiliary circuit thereof for governing the energization of saidmagnet.

' JOHN T. DOOLEY.

REFERENCES CITED The following. references are of record in the file'of'this patent:

UNITED STATES PATENTS Number Name Date 914,173 Norpoth Mar. 2,19021,814,255 Loeding July'l4,"l931 1,965,946 Pincus et a1. July 10, 19341,980,796 Golf Nov. 13, 1934 2,014,474 Hopkins Sept. 17, 1935 Y2,339,750 Bartho1y Jan. 25, 1944

